This invention relates to a mixing head of an injection molding machine in which two or more kinds of liquids are injected while mixing with each other under a high pressure.
The applicant has already proposed a type of an injection molding machine wherein two or more kinds of liquids are injected while mixing with each other under a high pressure.
In the earlier proposed injection molding machine, a mixing head has an injection plunger for opening and closing two orifices from which two kinds of liquids to be mixed are ejected under a pressure, and a spool plunger disposed perpendicular to the injection plunger for opening and closing two paths through which the two liquids are circulated. The injection plunger and spool plunger are moved synchronously and reciprocally by two oil cylinders, respectively.
However, in such an injection molding machine, as the reciprocal direction of the spool plunger is perpendicular to that of the injection plunger in the head portion of the mixing head, the head portion has an outer shape of many convex and concave portions and its weight is increased with a bulky shape. Therefore, the assembling of the mixing head in the injection molding machine is inconvenient.
Further, as the injection plunger and the spool plunger are located relatively far from each other, the oil passageways between both oil cylinders becomes long, so that the reciprocal movements of the injection plunger and the spool plunger are not easily carried out synchronously with each other.
Further, when the injection plunger and the spool plunger are moved, the directions of those movements are perpendicular to each other. Therefore, a twist force is exerted on the mixing head thereby to loosen the head portion on the machine. This decreases durability of the machine.